Adducts of polyamide and perfluoro-dicarboxylic acid

Abstract

Crystalline adducts of the polyamides: poly-e-caproamide, poly(hexamethylene adipamide), poly-p-benzamide, poly(p-benzanilidene terephthalamide), and mixtures thereof; with the perfluorinated diacids: perfluorosuccinic acid, perfluoroglutaric acid, perfluoroadipic acid, and mixtures thereof. The polyamide components of the adducts contain at least 25 about amide groups in the polymer chain, preferably at least 75 amide groups for aliphatic polyamides and at least 50 amide groups for aromatic polyamides. The adducts can be formed into shaped objects from which diacid can be leached to produce a porous object useful for example as a filtration device.

We claim: 
     
       1. A crystalline adduct of a polyamide having aminocarboxylic acid moieties and a perfluorodicarboxylic acid, in which the number of carbon and nitrogen atoms in one monomeric unit chain of an aminocarboxylic acid moiety of said polyamide is the same as the sum of the carbon atoms in one chain of said perfluorodicarboxylic acid plus 2, within ±1. 
     
     
       2. A crystalline adduct of a polyamide of the group consisting of poly-e-caproamide, polyhexamethyleneadipamide, poly-p-benzamide, poly-p-phenyleneterephthalamide, poly-p-benzanilidene terephthalamide, and mixtures thereof, in 1:1 mole ratio of amide groups of the polymer: carboxylic acid groups provided by the total added dicarboxylic acid below specified; said dicarboxylic acid being of the group consisting of perfluorosuccinic acid, perfluoroglutaric acid, perfluoroadipic acid and mixtures thereof; and said polyamide containing at least about 25 amide groups in the polymer chain. 
     
     
       3. Adduct in accordance with claim 2 wherein aliphatic polyamide components contain at least 75 amide groups in the polymer chain and aromatic polyamide components contain at least 50 amide groups in the chain. 
     
     
       4. Adduct in accordance with claim 3 wherein the polyamide is poly-e-caproamide and the dicarboxylic acid is perfluorosuccinic acid; the melting point is about 108° C., and the Wide Angle X-Ray Diffraction pattern is as in attached FIG. 1, Curve A. 
     
     
       5. Adduct in accordance with claim 3 wherein the polyamide is poly-e-caproamide and the dicarboxylic acid is perfluoroglutaric acid; the melting point is about 111° C.; and the Wide Angle X-Ray Diffraction pattern is as in attached FIG. 1, Curve B. 
     
     
       6. Adduct in accordance with claim 3 wherein the polyamide is poly-e-caproamide and the acid is perfluoroadipic acid; and the Wide Angle X-Ray Diffraction pattern is as in attached FIG. 1, Curve C. 
     
     
       7. Adduct in accordance with claim 3 wherein the polyamide is polyhexamethyleneadipamide and the dicarboxylic acid is perfluoroglutaric acid; the melting point is about 75° C.; and the Wide Angle X-Ray Diffraction pattern is as in attached FIG. 2, Curve A. 
     
     
       8. Adduct in accordance with claim 3 wherein the polyamide is poly-p-benzamide and the dicarboxylic acid is perfluoroglutaric acid; and the Wide Angle X-Ray Diffraction pattern is as in attached FIG. 3, Curve A. 
     
     
       9. Adduct in accordance with claim 3 wherein the polyamide is poly-p-phenyleneterephthalamide and the dicarboxylic acid is perfluoroglutaric acid. 
     
     
       10. A crystalline adduct of a polyamide having diamine moieties and dicarboxylic moieties and a perfluorocarboxylic acid; in which the number of carbon and nitrogen atoms of a monomeric unit chain of a diamine moiety of said polyamide and the number of carbon atoms in one monomeric unit chain of dicarboxylic acid moiety of the polyamide: (a) are equal within two atoms; and   (b) have a mean within ±1 of the sum of carbon atoms in one claim of said perfluorodicarboxylic acid plus 2.   
     
     
       11. Adduct in accordance with claim 1 or 10 wherein said polyamide comprises at least about 25 amide linkages in the polymer chain. 
     
     
       12. Adduct according to claim 11 wherein the mole ratio of amide groups in said polymer to carboxylic acid groups in said perfluorodicarboxylic acid is about 1 to about 1.